Postmortem Morphine Concentrations Following Use of a Continuous Infusion Pump

We report a case involving unusually high postmortem morphine concentrations in a 44-year-old male with end-stage pancreatic cancer. He was receiving morphine for pain control via a single subclavian intravenous catheter. Allegations of foul play were made by family members at the time of death, so a full autopsy was performed. Comprehensive toxicology on autopsy samples indicated that morphine was the only drug present. Quantitative analysis of free and total morphine revealed extraordinarily high concentrations of the drug. Free morphine concentrations in heart blood, vitreous fluid, brain, liver, stomach contents, and urine were 96 mg/L, 52 mg/L, 26 mg/kg, 88 mg/kg, 82 mg/L, and 976 mg/L, respectively. Total morphine concentrations in heart blood, vitreous fluid, brain, liver, and stomach contents were 421 mg/L, 238 mg/L, 65 mg/kg, 256 mg/kg, and 325 mg/L, respectively. Records indicate that the infusion pump may have continued to deliver the drug for 15-45 min following death. Despite compelling toxicological data, the cause of death was determined to be complication of adenocarcinoma of the pancreas, and the manner was natural. This report highlights issues surrounding postmortem toxicological interpretation within the context of chronic pain management.